1 files changed, 196 insertions, 0 deletions
diff --git a/src/mbgl/shaders/symbol_sdf.hpp b/src/mbgl/shaders/symbol_sdf.hpp
new file mode 100644
index 0000000000..67bcd86354
--- /dev/null
+++ b/src/mbgl/shaders/symbol_sdf.hpp
@@ -0,0 +1,196 @@
+#pragma once
+
+// NOTE: DO NOT CHANGE THIS FILE. IT IS AUTOMATICALLY GENERATED.
+
+#include <mbgl/gl/gl.hpp>
+
+namespace mbgl {
+namespace shaders {
+
+class symbol_sdf {
+public:
+    static constexpr const char* name = "symbol_sdf";
+    static constexpr const char* vertexSource = R"MBGL_SHADER(
+#ifdef GL_ES
+precision highp float;
+#else
+
+#if !defined(lowp)
+#define lowp
+#endif
+
+#if !defined(mediump)
+#define mediump
+#endif
+
+#if !defined(highp)
+#define highp
+#endif
+
+#endif
+
+float evaluate_zoom_function_1(const vec4 values, const float t) {
+    if (t < 1.0) {
+        return mix(values[0], values[1], t);
+    } else if (t < 2.0) {
+        return mix(values[1], values[2], t - 1.0);
+    } else {
+        return mix(values[2], values[3], t - 2.0);
+    }
+}
+vec4 evaluate_zoom_function_4(const vec4 value0, const vec4 value1, const vec4 value2, const vec4 value3, const float t) {
+    if (t < 1.0) {
+        return mix(value0, value1, t);
+    } else if (t < 2.0) {
+        return mix(value1, value2, t - 1.0);
+    } else {
+        return mix(value2, value3, t - 2.0);
+    }
+}
+
+// The offset depends on how many pixels are between the world origin and the edge of the tile:
+// vec2 offset = mod(pixel_coord, size)
+//
+// At high zoom levels there are a ton of pixels between the world origin and the edge of the tile.
+// The glsl spec only guarantees 16 bits of precision for highp floats. We need more than that.
+//
+// The pixel_coord is passed in as two 16 bit values:
+// pixel_coord_upper = floor(pixel_coord / 2^16)
+// pixel_coord_lower = mod(pixel_coord, 2^16)
+//
+// The offset is calculated in a series of steps that should preserve this precision:
+vec2 get_pattern_pos(const vec2 pixel_coord_upper, const vec2 pixel_coord_lower,
+    const vec2 pattern_size, const float tile_units_to_pixels, const vec2 pos) {
+
+    vec2 offset = mod(mod(mod(pixel_coord_upper, pattern_size) * 256.0, pattern_size) * 256.0 + pixel_coord_lower, pattern_size);
+    return (tile_units_to_pixels * pos + offset) / pattern_size;
+}
+const float PI = 3.141592653589793;
+
+attribute vec2 a_pos;
+attribute vec2 a_offset;
+attribute vec2 a_texture_pos;
+attribute vec4 a_data;
+
+
+// matrix is for the vertex position.
+uniform mat4 u_matrix;
+
+uniform mediump float u_zoom;
+uniform bool u_rotate_with_map;
+uniform bool u_pitch_with_map;
+uniform mediump float u_pitch;
+uniform mediump float u_bearing;
+uniform mediump float u_aspect_ratio;
+uniform vec2 u_extrude_scale;
+
+uniform vec2 u_texsize;
+
+varying vec2 v_tex;
+varying vec2 v_fade_tex;
+varying float v_gamma_scale;
+
+void main() {
+    vec2 a_tex = a_texture_pos.xy;
+    mediump float a_labelminzoom = a_data[0];
+    mediump vec2 a_zoom = a_data.pq;
+    mediump float a_minzoom = a_zoom[0];
+    mediump float a_maxzoom = a_zoom[1];
+
+    // u_zoom is the current zoom level adjusted for the change in font size
+    mediump float z = 2.0 - step(a_minzoom, u_zoom) - (1.0 - step(a_maxzoom, u_zoom));
+
+    // pitch-alignment: map
+    // rotation-alignment: map | viewport
+    if (u_pitch_with_map) {
+        lowp float angle = u_rotate_with_map ? (a_data[1] / 256.0 * 2.0 * PI) : u_bearing;
+        lowp float asin = sin(angle);
+        lowp float acos = cos(angle);
+        mat2 RotationMatrix = mat2(acos, asin, -1.0 * asin, acos);
+        vec2 offset = RotationMatrix * a_offset;
+        vec2 extrude = u_extrude_scale * (offset / 64.0);
+        gl_Position = u_matrix * vec4(a_pos + extrude, 0, 1);
+        gl_Position.z += z * gl_Position.w;
+    // pitch-alignment: viewport
+    // rotation-alignment: map
+    } else if (u_rotate_with_map) {
+        // foreshortening factor to apply on pitched maps
+        // as a label goes from horizontal <=> vertical in angle
+        // it goes from 0% foreshortening to up to around 70% foreshortening
+        lowp float pitchfactor = 1.0 - cos(u_pitch * sin(u_pitch * 0.75));
+
+        lowp float lineangle = a_data[1] / 256.0 * 2.0 * PI;
+
+        // use the lineangle to position points a,b along the line
+        // project the points and calculate the label angle in projected space
+        // this calculation allows labels to be rendered unskewed on pitched maps
+        vec4 a = u_matrix * vec4(a_pos, 0, 1);
+        vec4 b = u_matrix * vec4(a_pos + vec2(cos(lineangle),sin(lineangle)), 0, 1);
+        lowp float angle = atan((b[1]/b[3] - a[1]/a[3])/u_aspect_ratio, b[0]/b[3] - a[0]/a[3]);
+        lowp float asin = sin(angle);
+        lowp float acos = cos(angle);
+        mat2 RotationMatrix = mat2(acos, -1.0 * asin, asin, acos);
+
+        vec2 offset = RotationMatrix * (vec2((1.0-pitchfactor)+(pitchfactor*cos(angle*2.0)), 1.0) * a_offset);
+        vec2 extrude = u_extrude_scale * (offset / 64.0);
+        gl_Position = u_matrix * vec4(a_pos, 0, 1) + vec4(extrude, 0, 0);
+        gl_Position.z += z * gl_Position.w;
+    // pitch-alignment: viewport
+    // rotation-alignment: viewport
+    } else {
+        vec2 extrude = u_extrude_scale * (a_offset / 64.0);
+        gl_Position = u_matrix * vec4(a_pos, 0, 1) + vec4(extrude, 0, 0);
+    }
+
+    v_gamma_scale = gl_Position.w;
+
+    v_tex = a_tex / u_texsize;
+    v_fade_tex = vec2(a_labelminzoom / 255.0, 0.0);
+}
+)MBGL_SHADER";
+    static constexpr const char* fragmentSource = R"MBGL_SHADER(
+#ifdef GL_ES
+precision mediump float;
+#else
+
+#if !defined(lowp)
+#define lowp
+#endif
+
+#if !defined(mediump)
+#define mediump
+#endif
+
+#if !defined(highp)
+#define highp
+#endif
+
+#endif
+uniform sampler2D u_texture;
+uniform sampler2D u_fadetexture;
+uniform lowp vec4 u_color;
+uniform lowp float u_opacity;
+uniform lowp float u_buffer;
+uniform lowp float u_gamma;
+
+varying vec2 v_tex;
+varying vec2 v_fade_tex;
+varying float v_gamma_scale;
+
+void main() {
+    lowp float dist = texture2D(u_texture, v_tex).a;
+    lowp float fade_alpha = texture2D(u_fadetexture, v_fade_tex).a;
+    lowp float gamma = u_gamma * v_gamma_scale;
+    lowp float alpha = smoothstep(u_buffer - gamma, u_buffer + gamma, dist) * fade_alpha;
+
+    gl_FragColor = u_color * (alpha * u_opacity);
+
+#ifdef OVERDRAW_INSPECTOR
+    gl_FragColor = vec4(1.0);
+#endif
+}
+)MBGL_SHADER";
+};
+
+} // namespace shaders
+} // namespace mbgl